CN116097740A - Data transfer during mobility in layer 2 relay - Google Patents

Abstract

A User Equipment (UE) configured to operate as a relay UE between a remote UE and a base station. The relay UE receiving a data packet from an originating device for relay to a recipient device; determining that the relay of the data packet to the recipient device has failed; and sending a transmission comprising the data packet to the originating device, wherein the transmission comprises an indication that the data packet is being returned to the originating device.

Description

Data transfer during mobility in layer 2 relay

Background

A User Equipment (UE) may be configured with multiple communication links. For example, a UE may receive signals from a cell of a network over a downlink and may transmit signals to the cell over an uplink. The UE may also be configured to communicate with another UE via a side link. The term "side link" refers to a communication link that may be used for device-to-device (D2D) communication. The side link may be used as a radio relay link. For example, to facilitate communication between a network and a remote UE in a UE-to-network relay, the network may exchange signals with the relay UE via an uplink/downlink, and the relay UE may exchange signals with the remote UE via a side link.

The remote UE may be a mobile device that moves into and out of the coverage of a network cell. Thus, in some cases, the remote UE may communicate with the network cell via the relay UE, while in other cases, the remote UE may communicate directly with the network cell. When a remote UE changes from a relay connection to a direct connection, there may be data that has been sent to a relay UE intended for the remote UE or a network cell. The relay UE may no longer have a connection for forwarding data to the recipient device. This results in dropped data transmissions and a poor user experience.

Disclosure of Invention

Some example embodiments relate to a User Equipment (UE) configured to operate as a relay UE between a remote UE and a base station. The UE has: one or more processors; and a transceiver communicatively coupled to the one or more processors. The one or more processors are configured to perform operations. The operations include: receiving a data packet from an originating device for relay to a recipient device; determining that the relay of the data packet to the recipient device has failed; and sending a transmission comprising the data packet to the originating device, wherein the transmission comprises an indication that the data packet is being returned to the originating device.

Other exemplary embodiments relate to a baseband processor configured to perform operations. The operations include: receiving a data packet from an originating device for relay to a recipient device; determining that the relay of the data packet to the recipient device has failed; and sending a transmission comprising the data packet to the originating device. The transmission includes an indication that the data packet is being returned to the originating device and an original Radio Link Control (RLC) Protocol Data Unit (PDU) received from the originating device that includes the data packet.

Drawings

Fig. 1 illustrates an exemplary network arrangement according to various exemplary embodiments.

Fig. 2 illustrates an exemplary User Equipment (UE) in accordance with various exemplary embodiments.

Fig. 3 illustrates an exemplary base station in accordance with various exemplary embodiments.

Fig. 4 illustrates an example of UE-to-network relay in accordance with various exemplary embodiments.

Fig. 5A illustrates an example of UE-to-network relay user plane protocol stack signaling in accordance with various exemplary embodiments.

Fig. 5B illustrates an example of UE-to-network relay control plane protocol stack signaling in accordance with various exemplary embodiments.

Fig. 6 shows an exemplary signaling diagram for Downlink (DL) data exchange between a gNB and a remote UE.

Fig. 7 illustrates an exemplary signaling diagram for Downlink (DL) data exchange between a gNB and a remote UE, in accordance with various exemplary embodiments.

Fig. 8 illustrates an exemplary data encapsulation including a new UL MAC sub-header indicating that the data payload is routed back to DL data, in accordance with various exemplary embodiments.

Fig. 9A illustrates a first exemplary new UL MAC sub-header indicating that a data payload is routed back to DL data in accordance with various exemplary embodiments.

Fig. 9B illustrates a second exemplary new UL MAC sub-header indicating that the data payload is routed back to DL data in accordance with various exemplary embodiments.

Fig. 10 illustrates an exemplary data package including a UL adaptation header indicating that a data payload is routed back to DL data, according to various exemplary embodiments.

Fig. 11 shows an exemplary signaling diagram for Uplink (UL) data exchange between a gNB and a remote UE.

Fig. 12 illustrates an exemplary signaling diagram for Uplink (UL) data exchange between a gNB and a remote UE, in accordance with various exemplary embodiments.

Fig. 13 illustrates an exemplary data encapsulation including a new DL MAC sub-header indicating that a data payload is routed back to UL data, according to various exemplary embodiments.

Fig. 14A illustrates a first exemplary new DL MAC sub-header indicating that a data payload is routed back to DL data according to various exemplary embodiments.

Fig. 14B illustrates a second exemplary new DL MAC sub-header indicating that the data payload is routed back to UL data in accordance with various exemplary embodiments.

Detailed Description

The exemplary embodiments may be further understood with reference to the following description and the appended drawings, wherein like elements have the same reference numerals. The exemplary embodiments provide mechanisms for a relay UE to return a data packet to an originating device and for the originating device to retransmit the data packet to an intended recipient.

The exemplary embodiments are described with respect to a UE. However, references to UEs are provided for illustration purposes only. The exemplary embodiments may be used with any electronic component that may establish a connection with a network and that is configured with hardware, software, and/or firmware for exchanging information and data with the network. Thus, the UE described herein is used to represent any electronic component.

The exemplary embodiments are also described with reference to a UE-to-network relay scenario. In a UE-to-network relay scenario, there may be a remote UE, a relay UE, and a cell. The term "remote UE" may refer to a UE that is configured as a remote end of a relay. The term "relay UE" may refer to a UE configured to act as a relay point between two remote endpoints of a relay. In this example, the other remote endpoint is a cell. To facilitate communication between a remote UE in a UE-to-network relay and the network, the cell may exchange signals with the relay UE via an uplink and/or downlink Uu connection, and the relay UE may exchange signals with the remote UE via a sidelink connection. Thus, the remote UE may access network services via the relay UE.

As described above, the remote UE may move into a network cell coverage area where the remote UE may be able to establish a direct connection with the cell, e.g., the remote UE may establish a Uu connection with the cell. To maintain consistency throughout this description, the remote UE will continue to be referred to as remote UE even when the remote UE establishes a direct Uu connection to the cell. It should also be appreciated that the remote UE may establish a Uu connection with the network for other reasons unrelated to moving into the cell coverage area. Thus, the exemplary embodiments are not limited to any particular mobility scenario, but may be applied to any scenario in which a remote UE changes from a relay connection to a direct connection to a network.

Fig. 1 illustrates an exemplary network arrangement 100 according to various exemplary embodiments. The exemplary network arrangement 100 includes UEs 110, 112. Those skilled in the art will appreciate that UEs 110, 112 may be any type of electronic component configured to communicate via a network, such as, for example, components of a networked automobile, a mobile phone, a tablet computer, a smart phone, a tablet, an embedded device, a wearable device, an internet of things (IoT) device, and so forth. An actual network arrangement may include any number of UEs used by any number of users. Thus, the example with two UEs 110, 112 is provided for illustration purposes only.

The UEs 110, 112 may communicate directly with one or more networks. In an example of network configuration 100, the networks with which UEs 110, 112 may wirelessly communicate are a 5G NR radio access network (5G NR-RAN) 120, an LTE radio access network (LTE-RAN) 122, and a Wireless Local Area Network (WLAN) 124. However, UE 110 may also communicate with other types of networks, and UE 110 may also communicate with networks through wired connections. Thus, UEs 110, 112 may include a 5G NR chipset in communication with 5G NR-RAN120, an LTE chipset in communication with LTE-RAN 122, and an ISM chipset in communication with WLAN 124.

The 5G NR-RAN 120 and LTE-RAN122 may be part of a cellular network that may be deployed by a cellular provider (e.g., verizon, AT & T, sprint, T-Mobile, etc.). These networks 120, 122 may include, for example, cells or base stations (NodeB, eNodeB, heNB, eNBS, gNB, gNodeB, macro, micro, small, femto, etc.) configured to transmit and receive traffic from UEs equipped with appropriate cellular chipsets. WLAN 124 may comprise any type of wireless local area network (WiFi, hotspot, IEEE 802.11x network, etc.).

UEs 110, 112 may connect to the 5G NR-RAN via the gNB 120A. The gNB 120A may be configured with the necessary hardware (e.g., antenna array), software, and/or firmware to perform massive multiple-input multiple-output (MIMO) functions. Massive MIMO may refer to a base station configured to generate multiple beams for multiple UEs. Reference to a single gNB 120A is for illustrative purposes only. The exemplary embodiments may be applied to any suitable number of gnbs. UEs 110, 112 may also be connected to LTE-RAN122 via eNB 122A.

Those skilled in the art will appreciate that any associated procedure may be performed for the UEs 110, 112 to connect to the 5G NR-RAN 120 and the LTE-RAN 122. For example, as discussed above, 5G NR-RAN 120 and LTE-RAN122 may be associated with a particular cellular provider where UEs 110, 112 and/or users thereof have contract and credential information (e.g., stored on a SIM card). Upon detecting the presence of 5G NR-RAN 120, UE110, 112 may transmit corresponding credential information for association with 5G NR-RAN 120. More specifically, the UEs 110, 112 may be associated with a particular base station (e.g., the gNB 120 of the 5G NR-RAN 120A, LTE-eNB 122A of the RAN 122).

In addition to networks 120, 122 and 124, network arrangement 100 also includes a cellular core network 130, the internet 140, an IP Multimedia Subsystem (IMS) 150, and a network services backbone 160. The cellular core network 130 may be considered an interconnected set of components that manage the operation and traffic of the cellular network. The cellular core network 130 also manages traffic flowing between the cellular network and the internet 140. IMS 150 may be generally described as an architecture for delivering multimedia services to UE110 using IP protocols. IMS 150 may communicate with cellular core network 130 and internet 140 to provide multimedia services to UE 110. The network services backbone 160 communicates with the internet 140 and the cellular core network 130 directly or indirectly. Network services backbone 160 may be generally described as a set of components (e.g., servers, network storage arrangements, etc.) that implement a set of services that may be used to extend the functionality of UE110 in communication with various networks.

Fig. 2 illustrates an exemplary UE110 in accordance with various exemplary embodiments. UE110 will be described with reference to network arrangement 100 of fig. 1. UE110 may include a processor 205, a memory arrangement 210, a display device 215, an input/output (I/O) device 220, a transceiver 225, and other components 230. Other components 235 may include, for example, audio input devices, audio output devices, power sources, data acquisition devices, ports for electrically connecting UE110 to other electronic devices, and the like. UE110 shown in fig. 2 may also represent UE 112. UE110 described with respect to fig. 2 may act as a remote UE or a relay UE.

Processor 205 may be configured to execute multiple engines of UE 110. For example, the engines may include a routing back engine 235 and a retransmission engine 240. When UE 110 is functioning in the capability of a relay UE, routing back engine 235 may perform operations related to routing UL or DL data packets back to the device from which the data packet originated. Retransmission engine 240 may perform operations related to receiving UL data packets originated by UE 110 and retransmitting UL data packets on different links. Examples of operations related to the routing back engine 235 and the retransmission engine 240 are described in more detail below.

The above-described engines are each merely exemplary as an application (e.g., program) that is executed by the processor 205. The functionality associated with the engine may also be represented as a separate integrated component of UE 110 or may be a modular component coupled to UE 110, e.g., an integrated circuit with or without firmware. For example, an integrated circuit may include input circuitry for receiving signals and processing circuitry for processing signals and other information. The engine may also be embodied as an application or as separate applications. Further, in some UEs, the functionality described for processor 205 is shared between two or more processors, such as a baseband processor and an application processor. The exemplary embodiments may be implemented in any of these or other configurations of the UE.

Memory arrangement 210 may be a hardware component configured to store data related to operations performed by UE 110. The display device 215 may be a hardware component configured to display data to a user, while the I/O device 220 may be a hardware component that enables user input. The display device 215 and the I/O device 220 may be separate components or may be integrated together (such as a touch screen). The transceiver 225 may be a hardware component configured to establish a connection with the UE 112, 5G NR-RAN 120, LTE-RAN 122, WLAN 122, etc. Thus, transceiver 225 may operate on a plurality of different frequencies or channels (e.g., a contiguous set of frequencies).

Fig. 3 illustrates an exemplary network cell, in this example, a gNB 120A, in accordance with various exemplary embodiments. The gNB 120A may represent any access node of a 5G NR network that the UE 110 may use to establish a connection.

The gNB 120A may include a processor 305, a memory arrangement 310, an input/output (I/O) device 320, a transceiver 325, and other components 330. Other components 330 may include, for example, power supplies, data acquisition devices, ports that electrically connect the gNB 120A to other electronic devices, and the like.

Processor 305 may be configured to execute multiple engines of gNB 120A. For example, the engine may include a retransmission engine 335 for performing operations related to receiving DL data packets originated by the gNB 120A and retransmitting the DL data packets on different links. Examples of the receiving and retransmitting operations will be described in more detail below.

The above-described engines are merely exemplary as application programs (e.g., programs) that are executed by the processor 305. The functionality associated with the engine may also be represented as a separate integrated component of the gNB 120A, or may be a modular component coupled to the gNB 120A, such as an integrated circuit with or without firmware. For example, an integrated circuit may include input circuitry for receiving signals and processing circuitry for processing signals and other information. Further, in some gnbs, the functionality described for the processor 305 is split between multiple processors (e.g., baseband processors, application processors, etc.). The example aspects may be implemented in any of these or other configurations of the gNB.

Memory 310 may be a hardware component configured to store data related to operations performed by UEs 110, 112. The I/O device 320 may be a hardware component or port that enables a user to interact with the gNB 120A. Transceiver 325 may be a hardware component configured to exchange data with UE 110 and any other UE in system 100. The transceiver 325 may operate on a variety of different frequencies or channels (e.g., a set of consecutive frequencies). Accordingly, the transceiver 325 may include one or more components (e.g., radio components) to enable data exchange with various networks and UEs.

Fig. 4 illustrates an example of a UE-to-network relay 400 in accordance with various exemplary embodiments. Fig. 3 will be described with reference to network arrangement 100 of fig. 1 and UE 110 of fig. 2.

F-EF237002

UE-to-network relay 400 includes remote UE 110, relay UE 112, and the gNB 120A of 5g NR ran 120. Remote UE 110 may exchange signals with relay UE 112 via side link 410. In this example, side link 410 may represent a PC5 interface. However, the exemplary embodiments are not limited to a PC5 interface, and any suitable communication interface may be used between remote UE 110 and relay UE 112. Relay UE 112 may exchange signals with 5g NR RAN120 via gNB 120A. In this example, the connection 420 between the relay UE 112 and the 5g NR RAN120 may represent a Uu interface. However, the exemplary embodiments are not limited to the Uu interface, and any suitable communication interface may be used between relay UE 112 and 5g NR RAN 120.

Remote UE 110 may access network services from 5g NR RAN120 via UE-to-network relay 400. For example, remote UE 110 may transmit information and/or data intended for 5g NR RAN120 to relay UE 112 via side link 410. Relay UE 112 may then transmit information and/or data intended for 5g NR RAN120 to 5gnr RAN120 via connection 420. Similarly, the 5gnr RAN120 may transmit information and/or data intended for the remote UE 110 to the relay UE 112 via connection 420. Relay UE 112 may then transmit information and/or data intended for remote UE 110 to remote UE 110 via side link 410. Thus, the gNB 120A may be able to access and control the remote UE 110 via the UE-to-network relay 400.

Fig. 5A illustrates an example of UE-to-network relay 500 user plane protocol stack signaling in accordance with various exemplary embodiments. Fig. 5B illustrates an example of UE-to-network relay 550 control plane protocol stack signaling in accordance with various exemplary embodiments. As can be seen from fig. 5A and 5B, for the protocol architecture for the user plane and the control plane, relaying is performed above the Radio Link Control (RLC) sub-layer. In these examples, the Uu Packet Data Convergence Protocol (PDCP) layer and the Radio Resource Control (RRC) layer terminate between the remote UE112 and the gNB 120A. In contrast, radio Link Control (RLC), medium Access Control (MAC), and Physical (PHY) layers, and non-3 GPP transport layers terminate in each link.

Downlink (DL) transmission

Fig. 6 illustrates an exemplary signaling diagram 600 for Downlink (DL) data exchange between the gNB 120A and the remote UE112. Signaling diagram 600 is described with respect to network arrangement 100 of fig. 1 and UE-to-network relay of fig. 4. In 605, the UE-to-network relay may be considered configured and active. For example, in the DL direction, the gNB 120A may send a data packet intended for the remote UE112 to the relay UE 110, which relay UE 110 may then forward the data packet to the remote UE112. The signaling diagram 600 will be described from the perspective of a single DL data packet, but it should be understood that more than one DL data packet may undergo signaling of the signaling diagram 600.

In 610, the gNB 120A has a data packet for the remote UE 112. The gNB 120A transmits data packets to the relay UE 110 according to the UE-to-network relay scheme. In 615, relay UE 110 sends an Acknowledgement (ACK) to the gNB 120A indicating that the data packet has been successfully received. In 625, relay UE 110 forwards the data packet to remote UE 112. However, in this example, DL data transmission 625 from relay UE 110 to remote UE 112 fails. The reason for this failure is that the remote UE 112 performs path switching in 620. Path switch 620 means that remote UE 112 has switched from the UE-to-network relay scheme to a direct Uu connection with gNB 120A. Thus, the side link connection (e.g., PC5 connection) between remote UE 112 and relay UE 110 is no longer active and DL data transfer 625 fails.

Meanwhile, in 630, it is shown that the gNB 120A has refreshed the DL buffer. Those skilled in the art will appreciate that the gNB 120A may have a portion of memory as a DL buffer. The DL buffer will hold DL data packets until the gNB 120A has been informed that the DL data packets have been successfully received by the receiving device or, in some cases, for a predetermined amount of time. After successful reception or a predetermined amount of time, the data packets are refreshed from the DL buffer. In this example, the gNB 120A receives an ACK 615 for the exemplary DL data packet from the relay UE 110. The UE-to-network relay scheme is a hop-by-hop relay, and therefore, the gNB 120A believes that the DL data packet has been successfully received by the receiving device and that the data packet may be refreshed from the DL buffer.

For example, due to path switch operation 620, the Uu connection between remote UE 1123 and gNB 120A may be considered to be configured and active at 635. In this regard, however, it should be appreciated that remote UE112 has not received the DL data packet, relay UE 110 has the DL data packet, and the gNB 120A has refreshed the DL data packet from the DL buffer because it erroneously believes that the DL data packet has arrived at the intended recipient. In this scenario, the DL data packet is stranded at relay UE 110 without a way to reach the intended recipient remote UE 112. The exemplary embodiments provide a way to route stranded DL data packets to the intended recipient remote UE 112.

Fig. 7 illustrates an exemplary signaling diagram 700 for Downlink (DL) data exchange between the gNB 120A and the remote UE112, in accordance with various exemplary embodiments. Signaling diagram 600 is described with respect to network arrangement 100 of fig. 1 and UE-to-network relay of fig. 4. As will be described in more detail below, in some example embodiments, a new MAC sub-header may be introduced to identify DL packets routed back to the gNB 120A because the relay UE 110 cannot successfully forward the data packets to the remote UE112 due to path switching by the remote UE 112. In other example embodiments, the modified UL adaptation may be introduced to identify DL packets that are routed back to the gNB 120A.

The signaling 705 to 735 of signaling diagram 700 may be similar to signaling 605 to 635 of signaling diagram 600. Therefore, the signaling will not be described again. As described above, at 735, remote UE112 has not received the DL data packet, relay UE110 has the DL data packet, and gNB 120A has refreshed the DL data packet from the DL buffer because it erroneously believes that the DL data packet has arrived at the intended recipient.

In some example embodiments, relay UE112 may perform a routing back 740 to send the data packet back to the gNB 120A. Relay UE110 may return the data packet to gNB 120A. However, because the routed-back transmission 740 is a return of previously transmitted DL data to the gNB 120A, rather than the normal UL data transmission that the gNB 120A would expect from the relay UE110, the relay UE110 may identify the routed-back transmission 740 as such a return of DL data to the gNB 120A.

In some example embodiments, the routed back transmission 740 may include a new UL MAC sub-header that indicates that the data payload (e.g., data packet) is routed back to the data. Fig. 8 illustrates an exemplary data package 800 including a new UL MAC sub-header 810 indicating that the data payload is routed back to DL data, in accordance with various exemplary embodiments. The data encapsulation 800 includes a new UL MAC sub-header 810, a UL RLC header 820, a UL adaptation header 830, and DL data packets 840 originally intended for the remote UE 112. The new UL MAC sub-header will be described in more detail below with reference to fig. 9A and 9B. UL RLC header 820 and UL adaptation header 830 may be considered normal headers associated with UL data transmissions. The data payload 840 may be an original DL RLC Protocol Data Unit (PDU) to allow the gNB 120A to distinguish between original Data Radio Bearers (DRBs).

Fig. 9A illustrates a first exemplary new UL MAC sub-header 900 indicating that a data payload is routed back to DL data, according to various exemplary embodiments. The new UL MAC sub-header 900 includes a type field 910, a format (F) field 920, and a Logical Channel Identification (LCID) field 930 in the first octet, and a LCID field 940 in the second octet. In this exemplary embodiment, the type field 910 may include an indication that the data payload is routed back to DL data. For example, the type field 910 may be a one-bit field set to "1" when the data payload is routed back to DL data.

Returning to the signaling diagram 700 of fig. 7, the routed back transmission 740 may be encapsulated as shown in the example data encapsulation 800 of fig. 8 to include a new UL MAC sub-header (e.g., new MAC sub-header 900) that includes an indication of whether the data payload is routed back to DL data. When the gNB 120A receives and decodes the routed back transmission 740, the gNB 120A will know that the data payload is routed back to DL data.

In 745, the gNB 120A may then send a DL data transmission to the remote UE 112 via the Uu connection, the DL data transmission comprising the data packets returned to the gNB 120A by the relay UE 110. The gNB 120A may decrypt and re-encrypt the data packet before sending out the routed-back DL data to the remote UE 112 over the Uu interface, as the data was sent via a different connection, the original encryption may not be valid.

In some example embodiments, a timer may be introduced for relay UE 110. The timer may begin when a relay link between relay UE 110 and remote UE 112 expires. Relay UE 110 may route data packets intended for remote UE 112 back to gNB 120A until the timer expires. When the timer expires, relay UE 110 may discard any remaining data packets. The data packet may be discarded because when the timer expires, the data in the data packet is likely stale and there is no reason to route the stale data back to the gNB 120A.

The data packets routed back to the gNB 120A may be associated with quality of service (QoS) processing. Thus, when a data packet is routed back to the gNB 120A in the routing back transmission 740, the data packet should be retransmitted to the remote UE 112 (e.g., DL data transmission 745) using the same QoS requirements. However, configuring DRBs according to service requirements may not be feasible because relay UE 110 cannot understand the traffic pattern of DL data for remote UE 112.

In some example embodiments, the routed-back transmission 740 may use a default DRB to carry the routed-back data. In other example embodiments, the routed-back transmission 740 may use the reflective UL DRBs to carry the routed-back data. It will be appreciated by those skilled in the art that in a reflective QoS DRB scheme, one or more DL DRBs may correspond to one or more UL DRBs, where the corresponding DRBs are referred to as reflective DRBs. These corresponding or reflective DRBs may be associated with the same QoS requirements. Thus, when routing back data, relay UE 110 may understand DL DRBs for the original transmission of the data (e.g., DL data transmission 710) and use the reflected DRBs for routing back transmission 740. In this way, when the gNB 120A receives the routed back transmission 740 on the reflective DRB, the gNB 120A implicitly understands the QoS requirements for the data that has been returned.

In other exemplary embodiments, the routed back transmission 740 may include a new UL MAC sub-header encapsulated in the same manner as shown in fig. 8. However, in these exemplary embodiments, the new UL MAC sub-header may be formatted differently to indicate that the data payload is routed back to DL data.

Fig. 9B illustrates a second exemplary new UL MAC sub-header 850 indicating that the data payload is routed back to DL data, according to various exemplary embodiments. The new UL MAC sub-header 950 includes a reserved (R) field 960 in the first octet, a format (F) field 970 and LCID field 980, and a LCID field 990 in the second octet. In this exemplary embodiment, LCID field 980 may include a predefined logical channel for functioning similarly to a tunnel routing back DL data.

Returning again to signaling diagram 700 of fig. 7, routing back transmission 740 may be encapsulated as shown in exemplary data encapsulation 800 of fig. 8 to include a new UL MAC sub-header (e.g., new MAC sub-header 950) that includes an indication of whether the data payload is routed back to DL data (e.g., an identification of a predefined logical channel in LCID field 980). When the gNB 120A receives and decodes the routed back transmission 740, the gNB 120A will learn that the data payload is routed back to DL data based on the predefined logical channels in the new MAC sub-header 950. In these exemplary embodiments, the QoS treatment may be based on a predefined DRB for carrying the data being routed back. The gNB 120A may then send a DL data transmission 745 to the remote UE 112 via the Uu connection, the DL data transmission comprising data packets returned to the gNB 120A by the relay UE 110.

In still other example embodiments, the routed back transmission 740 may use an UL adaptation header that includes an indication that the data payload is routed back to DL data. In these exemplary embodiments, it may not be necessary to introduce a new MAC sub-header as described above. This may allow the old header to remain intact without any alterations.

Fig. 10 illustrates an exemplary data package 1000 including a UL adaptation header 1030 indicating that a data payload is routed back to DL data, according to various exemplary embodiments. The data encapsulation 1000 includes a MAC sub-header 1010, a UL RLC header 1020, a UL adaptation header 1030, and DL data packets 940 originally intended for the remote UE 112. MAC sub-header 1010 and UL RLC header 1020 may be considered normal headers associated with UL data transmissions. As will be appreciated by those skilled in the art, the adaptation layer is a concept that is still determined for 3GPP communications. In this exemplary embodiment, it is suggested that UL adaptation header 1030 will include an identification of routed-back DL data that identifies remote UE 112 and/or relay UE 110 and the corresponding bearer, including routing back transmission 740. In this way, the gNB 120A will understand that the routing back transmission 740 is routed back to the DL data.

Returning again to the signaling diagram 700 of fig. 7, the routed-back transmission 740 may be encapsulated as shown in the exemplary data encapsulation 1000 of fig. 10 to include an UL adaptation header 1030 that includes an indication of whether the data payload is routed back to DL data. When the gNB120A receives and decodes the routed back transmission 740, the gNB120A will learn that the data payload is routed back to DL data based on the UL adaptation header 1030. The gNB120A may then send a DL data transmission 745 to the remote UE 112 via the Uu connection, the DL data transmission comprising the data packets returned to the gNB120A by the relay UE 110.

In these exemplary embodiments, the QoS treatment may be similar to the QoS treatment described above, e.g., the routed back transmission 740 may be sent via a default DRB or a reflective DRB.

Uplink (UL) transmission

Fig. 11 shows an exemplary signaling diagram 1100 for Uplink (UL) data exchange between the gNB120A and the remote UE 112. The signaling diagram 1100 is described with respect to the network arrangement 100 of fig. 1 and the UE-to-network relay 400 of fig. 4. In 1005, the UE-to-network relay 400 may be considered configured and active. For example, in the Uplink (UL), remote UE 112 may send a data packet intended for gNB120A to relay UE 110, which then forwards the data to gNB 120A. The signaling diagram 1100 will be described from the perspective of a single UL data packet, but it should be understood that more than one UL data packet may experience the signaling of the signaling diagram 1100.

In 1110, the remote UE112 has a data packet for the gNB120A. According to the UE-to-network relay scheme, remote UE112 transmits data packets to relay UE 110. In 1115, relay UE 110 sends an Acknowledgement (ACK) to remote UE112 indicating that the data packet has been successfully received. In 1120, remote UE112 flushes the UL buffer. In 1125, the remote UE112 performs a path switch from the UE-to-network relay scheme to a direct Uu connection with the gNB120A. In 1130, relay UE 110 forwards the data packet to gNB120A. However, in this example, UL data transmission 1130 from relay UE 110 to gNB120A fails because the relay connection is no longer active. Thus, similar to the problems described above with respect to DL, in this scenario, UL data packets are stranded at relay UE 110 without a way to reach intended recipient gNB120A. The exemplary embodiments provide a way to route stranded UL data packets to the intended recipient gNB120A.

Fig. 12 illustrates an exemplary signaling diagram 1200 for Uplink (UL) data exchange between the gNB120A and the remote UE112, in accordance with various exemplary embodiments. The signaling diagram 1120 is described with respect to the network arrangement 100 of fig. 1 and the UE-to-network relay 400 of fig. 4. As will be described in more detail below, in some example embodiments, a new DL MAC sub-header may be introduced to identify UL packets routed back to remote UE112 because relay UE 110 cannot successfully forward data packets to gNB120A due to a Uu link failure between relay UE 110 and gNB120A. Uu link failure may be related to path switching by remote UE112 or any other reason that prevents relay UE 110 from forwarding UL packets to gNB120A.

The signaling 1205 through 1235 of signaling diagram 1200 may be similar to the signaling 1105 through 1135 of signaling diagram 1100. Therefore, the signaling will not be described again. As described above, at 1235, gNB 120A has not received the UL data packet, relay UE 110 has the UL data packet, and remote UE 112 has refreshed the UL data packet from the UL buffer because it erroneously believes that the UL data packet has arrived at the intended recipient.

In some example embodiments, the relay UE 112 may perform a route backhaul transmission 1240 to send the data packet back to the remote UE 112. Relay UE 110 may return the data packet to remote UE 112. However, because the routed-back transmission 1240 is a return of previously transmitted UL data to the remote UE 112, rather than the remote UE 112 would expect a normal DL data transmission from the relay UE 110, the relay UE 110 may identify the routed-back transmission 1140 as such a return of UL data to the remote UE 112.

In some example embodiments, the route backhaul transport 1240 may include a new DL MAC sub-header indicating that a data payload (e.g., a data packet) is routed back to the data. Fig. 13 illustrates an exemplary data package 1300 including a new DL MAC sub-header 1310 indicating that a data payload is routed back to UL data, according to various exemplary embodiments. The data encapsulation 1300 includes a new DL MAC sub-header 1310, a DL RLC header 1320, and UL data packets 1330 originally intended for the gNB 120A. The new DL MAC sub-header 1310 will be described in more detail below with reference to fig. 14A and 14B. DL RLC header 1320 may be considered a normal header associated with DL data transmissions. The data payload 1330 may be an original UL RLC PDU to allow the remote UE 112 to distinguish between original DRBs.

Fig. 14A illustrates a first exemplary new DL MAC sub-header 1400 indicating that a data payload is routed back to UL data in accordance with various exemplary embodiments. The new DL MAC sub-header 1400 includes a type field 1410 in a first octet, a format (F) field 1420, and an LCID field 1430, and an LCID field 1440 in a second octet. In this exemplary embodiment, the type field 1410 may include an indication that the data payload is routed back to UL data. For example, the type field 1410 may be a one-bit field set to "1" when the data payload is routed back to UL data.

Returning to the signaling diagram 1200 of fig. 12, the routed back transmission 1240 may be encapsulated as shown in the example data encapsulation 1300 of fig. 13 to include a new DL MAC sub-header (e.g., the new DL MAC sub-header 1400) that includes an indication of whether the data payload is routed back to UL data. When remote UE 112 receives and decodes the routed-back transmission 1240, remote UE 112 will know that the data payload was routed back to UL data.

In 1245, remote UE 112 may then send an UL data transmission to gNB 120A via the Uu connection, the UL data transmission including the data packets returned to remote UE 112 by relay UE 110. The remote UE 112 may decrypt and re-encrypt the data packet before sending the routed-back UL data over the Uu interface to the gNB 120A, as the data is sent via a different connection, the original encryption may not be valid.

In some example embodiments, a timer may be introduced for relay UE 110. The timer may begin when a relay link between relay UE 110 and remote UE 112 expires. Relay UE 110 may route data packets intended for the gNB 120A back to the remote UE 112 until the timer expires. When the timer expires, relay UE 110 may discard any remaining data packets. The data packet may be discarded because when the timer expires, the data in the data packet is likely stale and there is no reason to route the stale data back to the remote UE 112.

The data packets routed back to the gNB 120A may be associated with quality of service (QoS) processing. Configuring DRBs according to service requirements may not be feasible because relay UE 110 cannot understand the traffic pattern of UL data for remote UE 112. In some example embodiments, the routed-back transmission 1240 may use a default Side Link (SL) DRB to carry the routed-back data.

In other exemplary embodiments, the route backhaul transport 1240 may include a new DL MAC sub-header encapsulated in the same manner as shown in fig. 13. However, in these exemplary embodiments, the new DL MAC sub-header may be formatted differently to indicate that the data payload is routed back to UL data.

Fig. 14B illustrates a second exemplary new DL MAC sub-header 1450 indicating that data payloads are routed back to UL data in accordance with various exemplary embodiments. The new DL MAC sub-header 1450 includes a reserved (R) field 1460 in the first octet, a format (F) field 1470, and an LCID field 1480, and an LCID field 1490 in the second octet. In this exemplary embodiment, LCID field 1480 may include a predefined logical channel for functioning similarly to a tunnel routing back UL data.

Returning again to signaling diagram 1200 of fig. 12, the routed back transmission 1240 may be encapsulated as shown in the exemplary data encapsulation 1300 of fig. 13 to include a new DL MAC sub-header (e.g., new DL MAC sub-header 1450) that includes an indication of whether the data payload is routed back to UL data (e.g., an identification of a predefined logical channel in LCID field 1480). When remote UE112 receives and decodes the routing back transmission 1240, remote UE112 will learn that the data payload is routed back to UL data based on the predefined logical channel in new DL MAC sub-header 1450. In these exemplary embodiments, the QoS treatment may be based on predefined SL DRBs for carrying the routed-back data. Remote UE112 may then send UL data transmission 1245, including the data packets returned to remote UE112 by relay UE 110, to gNB 120A via the Uu connection.

Examples

In a first embodiment, an apparatus comprises: one or more processors configured to perform operations comprising: transmitting data packets to be relayed to a recipient device to a relay User Equipment (UE) via a first connection; receiving a transmission from the relay UE comprising the data packet and an indication that the data packet is being returned; and transmitting the data packet to the recipient device via a second connection.

In a second embodiment, the apparatus according to the first embodiment, wherein the operations further comprise receiving an Acknowledgement (ACK) from the relay device that the relay device received the data packet.

In a third embodiment, the apparatus according to the second embodiment, wherein the operations further comprise removing the data packet from the transmission buffer after receiving the ACK.

In a fourth embodiment, the device according to the first embodiment, wherein the operations further comprise decrypting the data packet from the transmission and re-encrypting the data packet before transmitting the data packet to the recipient device.

In a fifth embodiment, the apparatus according to the first embodiment, wherein the apparatus is a base station and the receiver apparatus is a remote UE, and wherein the indication is included in an Uplink (UL) Medium Access Control (MAC) header.

In a sixth embodiment, the apparatus according to the fifth embodiment, wherein the UL MAC header comprises a type field and the indication is included in the type field.

In a seventh embodiment, the apparatus according to the sixth embodiment, wherein the transmission is received on one of a default Data Radio Bearer (DRB) or a reflective DRB corresponding to the DRB used to transmit the data packet to the relay UE.

In an eighth embodiment, the apparatus of the seventh embodiment, wherein the UL MAC header comprises a Logical Channel Identification (LCID) field, and the indication comprises an identification of a predefined logical channel in the LCID field.

In a ninth embodiment, the apparatus according to the eighth embodiment, wherein the transmission is received on a Data Radio Bearer (DRB) corresponding to the predefined logical channel.

In a tenth embodiment, the apparatus according to the first embodiment, wherein the apparatus is a base station and the receiver apparatus is a remote UE, and wherein the indication is included in an Uplink (UL) adaptation header.

In an eleventh embodiment, the device according to the first embodiment, wherein the transmission comprises an original Radio Link Control (RLC) Protocol Data Unit (PDU) transmitted by the device comprising the data packet.

In a twelfth embodiment, the device according to the first embodiment, wherein the device is a remote UE and the receiver device is a base station, and wherein the indication is included in a Downlink (DL) Medium Access Control (MAC) header.

In a thirteenth embodiment, the device according to the twelfth embodiment, wherein the DL MAC header comprises a type field and the indication is included in the type field.

In a fourteenth embodiment, the apparatus according to the thirteenth embodiment, wherein the transmission is received on a default Side Link (SL) Data Radio Bearer (DRB).

In a fifteenth embodiment, the apparatus according to the twelfth embodiment, wherein the DL MAC header includes a Logical Channel Identification (LCID) field, and the indication includes an identification of a predefined logical channel in the LCID field.

In a sixteenth embodiment, the apparatus according to the fifteenth embodiment, wherein the transmission is received on a Side Link (SL) Data Radio Bearer (DRB) corresponding to the predefined logical channel.

In a seventeenth embodiment, a baseband processor of a base station is configured to perform operations comprising: transmitting data packets to be relayed to a remote User Equipment (UE) via a first connection to the UE; receiving a transmission from the relay UE comprising the data packet and an indication that the data packet is being returned; and transmitting the data packet to the remote UE via a second connection.

In an eighteenth embodiment, the baseband processor of the seventeenth embodiment, wherein the indication is included in an Uplink (UL) Medium Access Control (MAC) header.

In a nineteenth embodiment, the baseband processor according to the eighteenth embodiment, wherein the UL MAC header includes a type field, and the indication is included in the type field.

In a twentieth embodiment, the baseband processor of the nineteenth embodiment, wherein the transmission is received on one of a default Data Radio Bearer (DRB) or a reflected DRB corresponding to a DRB used to transmit the data packet to the relay UE.

In a twenty-first embodiment, the baseband processor of the eighteenth embodiment, wherein the UL MAC header comprises a Logical Channel Identification (LCID) field, and the indication comprises an identification of a predefined logical channel in the LCID field.

In a twenty-second embodiment, the baseband processor of the twenty-first embodiment, wherein the transmission is received on a Data Radio Bearer (DRB) corresponding to the predefined logical channel.

In a twenty-third embodiment, the baseband processor of the seventeenth embodiment, wherein the indication is included in an Uplink (UL) adaptation header.

In a twenty-fourth embodiment, a baseband processor of a remote UE is configured to perform operations comprising: transmitting data packets to be relayed to a base station via a first connection to a relay User Equipment (UE); a transmission received from the relay UE including the data packet and an indication that the data packet is being returned; and transmitting the data packet to the base station via a second connection.

In a twenty-fifth embodiment, the baseband processor of the twenty-fourth embodiment, wherein the indication is included in a Downlink (DL) Medium Access Control (MAC) header.

In a twenty-sixth embodiment, the baseband processor of the twenty-fifth embodiment, wherein the DL MAC header comprises a type field, and the indication is included in the type field.

In a twenty-seventh embodiment, the baseband processor of the twenty-sixth embodiment, wherein the transmission is received on a default Side Link (SL) Data Radio Bearer (DRB).

In a twenty-eighth embodiment, the baseband processor of the twenty-fifth embodiment, wherein the DL MAC header comprises a Logical Channel Identification (LCID) field, and the indication comprises an identification of a predefined logical channel in the LCID field.

In a twenty-ninth embodiment, the baseband processor of the twenty-eighth embodiment, wherein the transmission is received on a Side Link (SL) Data Radio Bearer (DRB) corresponding to the predefined logical channel.

Those skilled in the art will appreciate that the exemplary embodiments described above may be implemented in any suitable software configuration or hardware configuration or combination thereof. Exemplary hardware platforms for implementing the exemplary embodiments may include, for example, intel x 86-based platforms having a compatible operating system, windows OS, mac platform and MAC OS, mobile devices having operating systems such as iOS, android, etc. The exemplary embodiments of the above-described methods may be embodied as a program comprising code lines stored on a non-transitory computer readable storage medium, which when compiled, may be executed on a processor or microprocessor.

While this patent application describes various combinations of various embodiments, each having different features, those skilled in the art will appreciate that any feature of one embodiment may be combined with features of other embodiments in any manner not disclosed in the negative or functionally or logically inconsistent with the operation or said function of the apparatus of the disclosed embodiments.

It is well known that the use of personally identifiable information should follow privacy policies and practices that are recognized as meeting or exceeding industry or government requirements for maintaining user privacy. In particular, personally identifiable information data should be managed and processed to minimize the risk of inadvertent or unauthorized access or use, and the nature of authorized use should be specified to the user.

It will be apparent to those skilled in the art that various modifications can be made to the present disclosure without departing from the spirit or scope of the disclosure. Accordingly, the present disclosure is intended to cover modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalents.

Claims (27)

1. A User Equipment (UE) configured to operate as a relay UE between a remote UE and a base station, the UE comprising:

one or more processors configured to perform operations comprising:

receiving a data packet from an originating device for relay to a recipient device;

determining that the relay of the data packet to the recipient device has failed; and

Sending a transmission comprising the data packet to the originating device, wherein the transmission comprises an indication that the data packet is being returned to the originating device; and

a transceiver communicatively coupled to the one or more processors.

2. The UE of claim 1, wherein the originating device is the base station, and wherein the indication is included in an Uplink (UL) Medium Access Control (MAC) header.

3. The UE of claim 2, wherein the UL MAC header includes a type field and the indication is included in the type field.

4. The UE of claim 3, wherein the transmission is sent to the base station using one of a default Data Radio Bearer (DRB) or a reflected DRB corresponding to a DRB used to receive the data packet.

5. The UE of claim 2, wherein the UL MAC header includes a Logical Channel Identification (LCID) field, and the indication includes an identification of a predefined logical channel in the LCID field.

6. The UE of claim 5, wherein the transmission is sent to the base station using a Data Radio Bearer (DRB) corresponding to the predefined logical channel.

7. The UE of claim 1, wherein the originating device is the base station, and wherein the indication is included in an Uplink (UL) adaptation header.

8. The UE of claim 1, wherein determining that the relay of the data packet has failed is based at least on not receiving an Acknowledgement (ACK) from the recipient device.

9. The UE of claim 1, wherein the transmission comprises an original Radio Link Control (RLC) Protocol Data Unit (PDU) received from the originating device that included the data packet.

10. The UE of claim 1, wherein the operations further comprise:

determining that the relay link has terminated;

when it is determined that the relay link has terminated, starting a timer; and

and performing a transmitting operation until the timer expires.

11. The UE of claim 1, wherein the originating device is the remote UE, and wherein the indication is included in a Downlink (DL) Medium Access Control (MAC) header.

12. The UE of claim 11, wherein the DL MAC header comprises a type field and the indication is included in the type field.

13. The UE of claim 12, wherein the transmission is sent to the remote UE using a default Side Link (SL) Data Radio Bearer (DRB).

14. The UE of claim 11, wherein the DL MAC header comprises a Logical Channel Identification (LCID) field, and the indication comprises an identification of a predefined logical channel in the LCID field.

15. The UE of claim 14, wherein the transmission is sent to the remote UE using a Side Link (SL) Data Radio Bearer (DRB) corresponding to the predefined logical channel.

16. A baseband processor configured to perform operations comprising:

receiving a data packet from an originating device for relay to a recipient device;

determining that the relay of the data packet to the recipient device has failed; and

sending a transmission comprising said data packet to said originating device,

wherein the transmission includes an indication that the data packet is being returned to the originating device, an

Wherein the transmission comprises an original Radio Link Control (RLC) Protocol Data Unit (PDU) received from the originating device that included the data packet.

17. The baseband processor of claim 16, wherein the originating device is a base station, and wherein the indication is included in an Uplink (UL) Medium Access Control (MAC) header.

18. The baseband processor of claim 17, wherein the UL MAC header includes a type field and the indication is included in the type field.

19. The baseband processor of claim 18, wherein the transmission is sent to the base station using one of a default Data Radio Bearer (DRB) or a reflected DRB corresponding to a DRB used to receive the data packet.

20. The baseband processor of claim 17, wherein the UL MAC header includes a Logical Channel Identification (LCID) field and the indication includes an identification of a predefined logical channel in the LCID field.

21. The baseband processor of claim 20, wherein the transmission is sent to the base station using a Data Radio Bearer (DRB) corresponding to the predefined logical channel.

22. The baseband processor of claim 16, wherein the originating device is a base station, and wherein the indication is included in an Uplink (UL) adaptation header.

23. The baseband processor of claim 16, wherein the originating device is a remote UE, and wherein the indication is included in a Downlink (DL) Medium Access Control (MAC) header.

24. The baseband processor of claim 23, wherein the DL MAC header comprises a type field and the indication is included in the type field.

25. The baseband processor of claim 24, wherein the transmission is sent to the remote UE using a default Side Link (SL) Data Radio Bearer (DRB).

26. The baseband processor of claim 23, wherein the DL MAC header includes a Logical Channel Identification (LCID) field and the indication includes an identification of a predefined logical channel in the LCID field.

27. The baseband processor of claim 26, wherein the transmission is sent to the remote UE using a Side Link (SL) Data Radio Bearer (DRB) corresponding to the predefined logical channel.

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